Insurgents, be afraid. An armed, unmanned ground vehicle that never gets tired, hungry or scared is headed your way. The Sword has night and thermal vision, four cameras and a 7.62-mm machine gun. It can climb stairs and is utterly silentuntil it opens fire. A live video feed enables its "driver" to operate the vehicle from up to 1 mile away. The U.S. Army has ordered 18 to deploy in Iraq.